Focusing device for camera lenses



xIlz 1,417.52?

A. S. HOWELL.

FOCUSING -DEVICE FOR CAMERA LENSES.

APPLICATION FILED SEPT. 20, 1920.l

`Patented May 30, 1922.

@Bievres MNT erica.-

ALBERT S. HOWELL, CHICAGO, IL'IiIll'OIS.V ASSIGNOR TO BELL HOWELL COMPANY,

OF CHICAGO, ILLINOIS, A CORPORATION.OF ILLINOIS.

-Y rocusme DnvIcE'r-on CAMERA LENsEs.

To all whom it may concern:

Be it known` that I,`ALBERT S. HOWELL, a citizen of the United States, residing at Chicago, inthe county'of Cook-and' State of Illinois, have invented a certain new and use-A ful Improvement in Focusing Devices for Camera Lenses, of which the following is a full, clear, concise, and exact description, reference beinghad to theaccompanying4 drawings, forming a part of thisv specification. Y y

My invention relates to focusing devices for camera lenses and relates particularly to 4 tain other features hereinafter appearing are such a device for camera lenses of'motiou picture cameras although not limited' to this j use alone.

I have found that the adjustment of the iris diaphragm device has4 an effect upon the focus -of the lens, that is, the focal adjustment of the lens along it'saxis which is correct when the iris diaphragm device .is wide open is not'correctwhen the iris diaphragm device is partially closed for the focusing of the lens upon an object at a given distance from the camera, and that as the iris diaphragm is closed the distance between the lens and the sensitized plate or film should be increasedto effect an 'accurate focus of the lens in the several adjustments of the diaphragm. The main feature of my invention resides in the provisions of means whereby the adjustment ofthe focus of the,

lens both with relation to the distance between objects to be' focused and the'camera and with relation to the adjustment of the iris diaphragm devicemay be predetermined topermit such focal adjustment of the lens accurately and quickly. v

lVith this feature in Vview lmy invention consists in certain features of novelty in the construction, combination, and arrangement of parts by which the said feature and cereffected, all as fully described with reference to the accompanying drawings and more particularly pointed out in the claims.

In the said drawings- Figure 1 is a view in side elevation of a camera lens assembly embodying my invention in its preferred form. 4

Figure 2 is a central horizontal section on the line 2-2 of Figure 1.

i i. Specification of Letters Patent. Patented May 30, 1922 .Application led September 20, 1.920. Serial No. 411,514. l

section on the line of in various positions.

L ke charactersof reference indicate like `of the inventiongshowing the elements there- .parts in' the various Views. I

i In the drawings 7 designates a support element which is tubular instructure and is provided lwith an external circumferential fiange 8 by means of whichthe same may be easil secured to a camera casing. .A second ,tubu ar element 9, inwhich a camera lens 10- Eis.moun`ted, as hereinafter described, has ex ternal' screw-threads l'formed on the outer surface at the'rearward end thereof, which screw-threads engage corresponding internal screw-threads formed on the inner 'surface of the tube 7 at the rearward end thereof, as designated at 11. The lens '10 is secured within vthe tube 9 by means of an internally threaded bush 12 screw-threaded u on the rear end of the lens body 13 against t e usual flange 14 of this body and extending rearwardly therefrom and an externally flanged clamp ring 15 screw-threaded into the rear end of the bush 12 and having its flange en gaging the rear surface of an internal rib 16 formed on the tube 9, and clamping the rear end of thebush 412 against the front surface of this rib. See Fig'. 2. 4A headed screw 17 is disposed radially in a countersunk hole in the bush 12 and is screw-threaded into the lens body 13 to maintain the lens body and bush in' proper relation, and a radially 'disposed pin` 18 is secured in the tube 9 immediately in front of the internal rib 16 and extends inwardl and engages aslot 6 in the bush 12,exten ing longltudinally of the bush from the rear end thereof, to maintain the. bushand tube 9 in proper relation. The screwvthreaded en agement of the tubes 7 and 9 provides a ocal adjustment for the lens 10 lution of the tube 9 with relation to the tube tion of the tube 9, as designated at 1.9, and the portion of this tube between the groove and forward end of the tube, as designated at 20, is somewhat larger in internal diameter than the main portion of the bore of this tube rearward of the groove 19, this leaving a space between the portion of the tube 7 and the tube 9. Mounted for pivotal movement within the groove 19 on an axis coaxial with the axis of rotation of the tube 9 is a split resilient expansion ring 21, which extends forwardly of the front end of the tube 7 and has an external groove engaged with the portion 20 of the tube 7, the portion of this ring in line with the portion 20 of tube 7 occupying the space between the port-ion 20 and tube 9. The interengagement of the shoulders formed by the grooves of the tube 7 and ring 21 provides for end thrust of the. ring relatively to the tube. The ring 21 expands against the tube 7 and is assembled pivotal movement.

therein before the tube 9 is mounted in the tube by contracting the ring and then allowing it to expand against the tube 7 into its assembled position therewith. The resilient expanding nature of the ring 21 provides a frictional engagement between the ring and tube 7 and functions to maintain the same in its adjusted position therewith. The internal diameter of thering 21 is such-that the tube 9 will rotate freely with relation thereto. The portion of the tube 7 in line with the groove 19 is provided with two diametrically opposite circumferentially extending slots 22 in which are engaged the heads of respective diametrically disposed screws 23 screw-threaded into the ring 21. See Figs. 1 and 4. These screws by engagement in the slots limit the pivotal movement of the ring and their heads project slightly above the external surface of the tube 7 to permit the convenient manipulation of the'ring in its Mounted on the outer surface of the tube 7 forward of the flange 8 is a spring blade 24 which extends longitudinally of the tube and is secured thereto at its rearward end by a headed screw 25. See Figs. 1 and 2. The forward end of this blade is oflset away from the tube forming a surface 26 slanting outwardly from the tube and away from the rearward portion of the blade. Secured to the blade 24 intermediate its ends is a'pin 27 which extends inwardly through an aperture in the tube 7 to engage the tube 9 to provide a frictional engagement between these tubes to prevent accidental movement of the tube 9 within tube 7. This frictional engagement may be broken to permit the easy removal of tube 9 within tube 7 by a blade 28, pivotally secured to tube 7 by means of a headed screw 29 and havingits intermediate portion underlying the offset portion of the blade 24 and having the edge thereof facing portion 26 of the blade l24 beveled to engage the portion 26 and raise the intermediate portion of the blade 2 4 away from the tube 7 uwhen the blade 28 1s moved to move the beveled edge thereof against the portio`n 26 of the blade 24. This actuation lifts the pin 27 out of engagement with the tube 9 to permit the easy removal thereof from the tube 7. i

The forward end of the tube 7 is enlarged to accommodate front portion of tube 9 which is enlarged to 'recelve a third tube 30, which is rotatably mounted 'within the tube 9. The extreme forward end of the tube 9 is externallyenlarged, as designated at 31, forming a rearwardly facino' shoulder, and this portion of the bore' of tube 9 is enlarged accordingly forming a forwardly facing shoulder in the bore. The tube 30 is externally enlarged adjacent its forward end, as designatedat 32, forming a rearwardly facing shoulder. This enlarged portion 32 of the tube lies within the enlarged portion of the bore. of tube 9 within the enlarged portion 31 of the tube and has a circumference groove 33 therein which is engaged by la radially disposed screw 34 screw-threaded into the enlarged portion 31 of the tube 9 and engagingthe groove 33 retain the tube 30 within the tube 9. The lens l0 is provided with a usual adjustable iris diaphragm device 35 which is con- "trolled by an adjustment ring 36 mounted fur limited rotation on the lens body 13. Tli`e\ring 36 is provided with a longitudinal slot 37. which is engaged by a rearwardly projecting lug 38 formed on the rear end of the tube 30 to provide an operative con; nection between the ring 36 and tube 30 whereby the adjustment of the iris diaphragmedevice may be effected by rotatory movementpf the tube 30within tube 9.

An opening 39 is formed in the rearwardly facing shoulder'of theenlarged portion 31 of the tube 9, this leaving a portion of the rearwardly facing shoulder of the enlarged portion 32 of the tube 30 exposed. See Figs. 1, 2, and 3. An indexing device is provided for the iris diaphragm device to indicate predetermined adjustments ofthe same, which indexing device comprises a scale4() placed on the rearwardly facing surface of the enlarged portion 31 of tube 9 at the opening 39 and a mark 41 placed on the portion of the rearwardly 'facing shoulder of the enlarged portion 32 of tube 3() which is exposed by the opening 39 in the various adj ustments of the tube 3() relatively to tube 9. See Fig. 3. This arrangement of the indexing device permits the same being viewed from a pointat the rear ofthe forward end of the tubes, and is a particularly -convenient' arrangement in the use of my invention as hereinafter set forth.

A' scale 42 is placed on the portion of the tube 9 immediately in front of the forward vtermined adjustments of the ring end ofthe tube "7 and extends inv the direc-y tion of rotation of tube 9. This scale cooperates with an end 43 of the split ring 21 to forman indexing device. This indexin device is adapted to indicate, when the sp it ring 21 is properly adjusted with the tube 7, redetermined adjustments of the tube 9 with the-tube 7, and accordingly predetermined adjustments of thelens 10, in`

accordance with the distances between 'the objects to be focused and the support tube 7. A scale 44 is placed on the extreme forward end-of the tube 7 and cooperates with `a Scale placed onthe exposed circumferential portion ofthe split' ring 2l. The scale 44 and scale 45 extend inthe direction of pivotal movement of the ring 21 and cooperate to translate the `adjustments of the iris diaphragm devicevas indicated by the indexing device thereof to indicate prede- 36 rela- Y tively to the tube 7 to cooperate with the in- Adexing device comprising the scale 42 and the end 43 of the ring to predetermine the focal adjustments of the tube 9 relatively to the support tube 7, and accordingly the lens l0 relatively to tube 7, to predetermine the l adjustments of the lens 10 relatively to the support tube 7 both with 4relation to the aidjustments of the iris diaphragm device and with relation to the distances between the objects focused and the support tube 7. The indexing device comprising scales 44 and 45 is of the vernier type for the reason that the translated adjustments of the iris diaphragm device are relatively slight and an ordinary scale and mark would be somewhat confusing because the marks of the scale would necessarily be very close' together. The scale 44 comprises-a number of spaced ,marks corresponding in number to the number of marks in the scale 40 and having like characters arranged in similar order. The scale 45 comprises the same number of spaced marks as does the scale,

44, and each mark of the'scale45 is adapted to be registered vwith a respective'markof thevscale'44'in the movement of the ring' 21. Each mark ofthe scale 45 is so posi tioned relatively to the end 43 of the ring 421 thatwhen it. is registered with the respective mark ofthe scale 44 .the end 43 is disposed So that'the scale 42 coo erating with the end 43 predetermines the ocal adjustmentof the lens 'relatively to the distances between objects to befocused and the tube 7 in accordance with the indicated adjustment of the iris diaphragm device. Thus 1n Flgure 6 the .indicated'adjustment vof the `iris diaphragm .device is indicated by the character 11 of the scale 40. The. 'ring 21 is therefore adjusted so that the respective mark of the scale 45 registers with the mark of the scale 44 opposite the character 11 thereof, and the tube 9 is adjusted so that the proper` mark o'f the 'scale l42 registers V with the end 43, it being the-mark indicated bythe character 8 in said Fig. 6. Fig. `5y

shows the ring 21 adjusted at one end of its movement where it allows the scale 42 to cooperate with a usual mark 46 formed at a cut away portion at the forwardu end lof ythe tube 7,*which mark mayfbeused to lcooperate with the said scale 42 when it-is desired not to predetermine the focal ad*- justment of the tube lens with relation tothe adjustment of the iris diaphragm de- While I have herein shown and particularly described the preferred'embodiment of Inyfinventionll do'not wish to be' limited to the precise details ofconstruction shown as Y l changes 'may readily be made without- .de-

partingy from the spirit of my invention,

'but'.having thus described my invention I claim as new and desire Patent\the following j ssf to secure by Letters i. A 'device of the nanfa described in# I cludingcaggcamera lens, a support thereforl adapted to permit movement of the lens relatively thereto longitudinally of the axisiof the lens to permit the focusing of the lens,

.an adjustable iris diaphragm device for the lens, an indexing device'adaptd to indicate predetermined adjustmentsof the4 iris diaphragm device, and `an indexing device adapted to indicate predetermined focal adjustments of the lens relatively to said support both with relation to the distance between objects to be focused and the support land with relation to the adjustment of the iris device.`

2. A device of the nature described including a camera lens, a support therefor adapted tol permit movement-of the lens relativelyvthereto longitudinally of thel axis of 'the lensto permit the focusing of the lens,

an adjustable iris diaphragm device for the lens, an indexing device adapted to indicate predetermined adjustments of the iris diaphragm device, and anV indexing device justments of the lens Arelatively to the support and longitudinally-*of the axis of the lens, an indexing device adapted to indicatel -predetermined adjustments of the iris diaphragm device, and an indexing device for indicating predetermined focal adjustments `adapted to indicate predetermined focal adof the lens relatively to the support including cate predetermined relative positions between said movable index member and the support, said two last mentioned index devices and said movable index member being adapted to'cooperate to indicate predetermined focaladjustments of the lens relatively to said support both with relation to the distancebetween objects'to be focused and the lens and with relation to the adjustments of the iris diaphragm device as indicated by said first mentioned indexing de- 4. A device ofthe nature described including a camera lens element, a support element therefor adapted to permit movement' of the lens element relatively thereto longitudinally of the axis of .the lens element' to permit the focusing of the lens element, an adjustable iris diaphragm device for the lens element; an indexing device adapted to' indicate. predetermined adjustments of the iris daphragm device, and an indexing. device for.indicating'predetermined focal adjustmentseof the lens relatively to the support element including an index member movable independently of the lens and support elements and a scale device indicating redetermined adjustments between said index member and one ofsaid elements, said index member being adapted to be positioned relatively to the other element-,in such independent movement in accordance with the adjustments of-said iris diaphragm device to translate such adjustments to 'indicate with said scale .device predetermined focal adjustments of the lens element in accordance with adjustments ofthe iris diaphragm device and said scale` device being adapted to indicate with said adjusted positions of the index member'predetermined focal adjustments of the'rlens element in accordance'with the distances between the. objects to be focused;

and thesupport element.

5. A device of the nature 'described including a camera lens element; asuppo'rtlelement therefor adapted to permit movement of the lens element relatively thereto longitudinally of the axis of the lens element to permit the focusing of -the lens element; an adjustable iris diaphragm device for the lens element; an indexing device adapted to 1ndic-ate predetermined adjustments of the iris f diaphragm device; and an indexing device for indicating predetermined focal adjustments of the Ilens element relatively to the support element including an index member movable independently of the lens and support elements, ascale device indicatingpredetermined positions .between the support 'member, one of said scale devices being adapted to translate the adjustments of said iris diaphragm device as indicated by said first mentioned indexing device to indicate predetermined positions of said index memberrelatively to one oftsaid elements to indicate with the other scale device and said movable index member predetermined focal adjustments of the lens element in accordance with the indicated adjustmentsof the iris diaphragm device and the other scale device being adapted to indicate predetermined positions of the other of said elements with the index member to indicate with said one scale device and said movable index member predetermined focal adjustments ofthe lens element in accordancewith the distance between objects to be focused and the support element.

6. A device lof the nature described including a camera lens element; a support element therefor adapted topermit-movement of the.

lens element relatively thereto longitudinally of the axis of the lens element to permit the focusing of the lens element; an adjustableiris diaphragm device for the lens element; anindexing device' adapted to indicate predetermined adjustments of the iris diaphragnidevice; and an indexing device for indicatingpredetermined focal adjustments of the lens,V element relatively to the slipport element including an index member movable independentlyof the lens' and support elenntg'a scale device indicating predetermine` element .and\.index member, and a second scale device indicating predetermined positions between the".` lens element and index member, one of 'said scale devices being of the vernier type and being adapted to translate the adjustments of said iris diaphragm device as indicated by said first mentioned indexing device'to indicate predetermined positions of said index member relatively to one of said elements. to indicate with the other scale device and said movable index member predetermined focal adjustments of the lens element in accordance with the indicated adjustments of the iris diaphragm device and the other scale device being adapted to indicate predeterminedpositions o-f the other of said elements with the index member to indicate Vwith said one scale device and said movable index member predetermined focal adjustments of the lens element in accordance with the distances between objects to be focused and the support element.

7. A device of -the nature described including a' camera lens element, a support ele` positions between the support` V justments of the iris diaphragml device, and

effect adjusting movement of the vlens element relatively to the support element longitudinally of the axis of the lens by relative rotation of the lens and support elements on the axis of the lens element to effect focusing thereof, an adjustable'iris diaphragm device for the lens element, an indexing device adapted to indicate predetermined adan indexing device for indicating predetermined focal adjustments' ofthe lens element relatively tothe support element in cluding an index member pivotally mount. ed to be moved independently of thel lens and support elements on the axis ofthe lens element and a scale device indicating predetermined adjustments between said index member'and one of said elements, said index member being adaptedto be positioned relatively to the other element in such independent movement 'in accordance with theadj ustments of said diaphragm device to translate Ysuch adjustments toindicate with said scale device predetermined focal adjustments of the lens element in accordance with adjustments of the iris diaphragm device and said scale device .being adapted jto indicate with said adjusted positions of the 'index member 'predetermined focal adjustriunts of the lens element in accordance with the distances between objects to be focused, and the supe.-

port element.

. 8. A device of the nature described including a camera lens element; asupporteleinent therefor; a'screwrthread devicebetween the lens and support elements-adapted to effect adjusting movement of the lens ele-V ment relatively to the support'felement longitudinally of the axis of the len's element by relative rotation of the lens and support e1e-.

ments Ion the axis of the lenselement to effect focusing thereof; 'an adjustable iris diaphragm device for the lens element; an indexing device adapted to indicatepredeter mined adjustments of the iris diaphragm device; and an indexing device for indicating predetermined focal adjustments of the lens element relatively to the support element including an index member pivotally mount'- ed to be moved independently of the lens and support elements on Ithe'axis of the lens element, a scale device indicating predetermined positions between the support element and index member, and a'second scale device indicating predetermined positions between the lens element and index member,

` one of said scale devices being adapted to translate the adjustments of said iris diaphragm device as indicated by said .firstA mentioned indexing device to indicate predetermined positions of said index member relatively to one of said elements to indicate with the other scale device and said movable index member predetermined focal adjust'- ments of the lens element in accordance with vthe indicated yadjustments of the iris dia-- phragm device and the other scale device being adapted to indicate predetermined pol sitions of the other of said elements with the index member to indicate with said one scale device and movable index member predetermined focal adjustments of the lens element 'in accordance -with the distances between objects to be focused and the support element.

9. A device of the nature described includ- 75 ing a camera lens element; a support ele-v ment therefor; a screw thread device between the lens and support elements adapted A. to effect adjusting movement of the lens ele- I ment relatively to the support element longitudinally of the axis of the lens element by relative rotation ofthe lens and support elements on the axis of the lens element to effect focusing thereof; an adjustable iris diaphragm device for the lens element; an 35 `indexiixigndevice adapted to indicate predetermined adjustments of the iris diaphragm devlce; and an indexing device for indicat- .ingpredetermined focal adjustments of the lenselement relatively to the support ele- 'ment including an index member pivotally mounted'to be moved independently of the lens and support elements 0n the axis ofthe lens element, a scale device indicating predet termined positions between the support elevvment andindex member, and a second scale' device indicating predetermined positions. .between thelens element and index member, one of said scale devices being of the vernier 'type and being adapted to translate the .ad- 100 justments of said iris diaphragm device as indicated by said first mentioned indexing device to indicate predetermined positions of said indexmemb'er relatively to @ne -of said elements to indicate with the'other scale de- 105 'vice and said movable index member prede- -terminedfocal adjustments of the lens element in accordance with the indicated ad-A justments of the iris diaphragm device andV the .other scale device being` adaptedto indicate .predetermined positions of the other of j 'said elements -with the index member to in-` ydicate with said one'scale device and movable index member predetermined focal ad.`

justments of the lens element in accordance 115 with the distances between objects to be focused and the support element.

iio i device, and an indexing device for indicating predetermined adjustments of said second tubular element with said first mentioned tubular element to predetermine the focal adjustments of the lens and including an index member pivotally mounted on one of said tubular elements on the axis of said second tubular element and a scale device indicating predetermined adjustments between said index member and one of said tubular elements, said index member being adapted to be positioned relatively to the other tubular element in such independent movement in accordance with the adjustments of saidiris diaphragmdevice to translate such adjustments to indicate with said scale device predetermined adjustments of' the tubular members in effecting the focus of the lens in accordance with adjustments of the iris diaphragm device and said scale device being adapted to indicate with said Y adjusted positions of the index member predetermined focal adjustments of the lens in accordance with the distances between the objects-to be focused and the first mentioned tubular member.

11. A device of the nature described including a tubular support element; a second tubular element extending within the saine and having a screw-threaded engagement therewith to effect longitudinal adjustment of said tubular elements by relative rotation thereof; a camera lens mounted within the second tubular element and having the axis coincident. with the axis of rotation of the same and to move therewith; an adjustable iris diaphragm device therefor; an index de- Vice adapted to indicate predetermined adjustments of the iris diaphragm device; and

an indexingrdevioe for indicating predeter mined adjustments o-f said second tubular member with said first mentioned tubular element to predetermine the focal adjustments of the lens and including a split resilient ring interlocked with one of said tubular elements in coaxial disposition therewith `and adapted to be pivoted thereon, a

scale device indicating predetermined posi-V device and the other scale device being.

adapted to indicate redetermined positions of the other of said e ements with the ring to indicate with said one scale device and ring -portion ofy said enlarged portion and communicating with the enlarged portion of the bore thereof; a camera lens mounted within the second tubular element and having its axis extending in parallelism with the axis thereof; van adjustable iris diaphragm device for the lens including a third tubular element disposed for limited rotation within the bore of said second tubular lelement vand having an enlarged portion disposed within the enlarged portion of the bore of said second tubular element and forming a rearwardly facing shoulder visible through said opening of the second tubular"`element from a point rearwardly of the enlarged portion of the second tubular element; index (device adapted to indicate predetermined adjustments ofsaid iris diaphragm device including a scale and cooperating mark one of which is placed on the enlarged portion of the second tubular element adjacent said opening thereof and the other of which is placed upon the surface of said enlarged'-.portion of the third tubular element which is risible through said opening of the second tubular element in the relative movement thereof; and an indexing device for indicating predetermined longitudinal adjustments of the second tubular element with said tubular support element to predetermine the focal adjustments of the lens including a movably mounted index member disposed adjacent the front end of said tubular sup-port element, a Scale device indicating predeterminedpositions between `the support element and index member, and a.

second scale device indicating predetermined positions between the second tubular element and the index member, one of these two last mentioned scale devices being of the Vernier type and being adapted to translate the adjustments of said iris diaphragm device as indicated by said first mentioned indexing device to indicate predetermined positions of said index member relatively to one of said first and second mentioned tubular elements to indicate with the other of said two last mentioned scale devices and said movable index member predetermined adjustments of the lens in accordance with the member predetermined focal adjustments of the lens in accordance with the distances between objects to be focused and the tubular 10 Support element.

In witness whereof I hereunto alix my signature this sixteenth day of September, 1920, A. D.

ALBERT S."HOWELL. 

